util.format_satoshis: fix whitespaces param for non-zero precision

electrum/tests/test_util.py

@@ -52,16 +52,16 @@ class TestUtil(ElectrumTestCase):
                          format_fee_satoshis(1666/1000, precision=1))
 
     def test_format_satoshis_whitespaces(self):
-        self.assertEqual("     0.0001234 ",
-                         format_satoshis(12340, whitespaces=True))
-        self.assertEqual("     0.00001234",
-                         format_satoshis(1234, whitespaces=True))
+        self.assertEqual("     0.0001234 ", format_satoshis(12340, whitespaces=True))
+        self.assertEqual("     0.00001234", format_satoshis(1234, whitespaces=True))
+        self.assertEqual("     0.45831275", format_satoshis(Decimal("45831275."), whitespaces=True))
+        self.assertEqual("     0.45831275   ", format_satoshis(Decimal("45831275."), whitespaces=True, precision=3))
+        self.assertEqual("     0.458312757  ", format_satoshis(Decimal("45831275.7"), whitespaces=True, precision=3))
+        self.assertEqual("     0.45831275748", format_satoshis(Decimal("45831275.748"), whitespaces=True, precision=3))
 
     def test_format_satoshis_whitespaces_negative(self):
-        self.assertEqual("    -0.0001234 ",
-                         format_satoshis(-12340, whitespaces=True))
-        self.assertEqual("    -0.00001234",
-                         format_satoshis(-1234, whitespaces=True))
+        self.assertEqual("    -0.0001234 ", format_satoshis(-12340, whitespaces=True))
+        self.assertEqual("    -0.00001234", format_satoshis(-1234, whitespaces=True))
 
     def test_format_satoshis_diff_positive(self):
         self.assertEqual("+0.00001234", format_satoshis(1234, is_diff=True))

electrum/util.py

@@ -677,10 +677,13 @@ def format_satoshis(
     if len(fract_part) < num_zeros:
         fract_part += "0" * (num_zeros - len(fract_part))
     result = integer_part + DECIMAL_POINT + fract_part
-    # add leading/trailing whitespaces
+    # add leading/trailing whitespaces so that numbers can be aligned in a column
     if whitespaces:
-        result += " " * (decimal_point - len(fract_part))
-        result = " " * (15 - len(result)) + result
+        # add trailing whitespaces
+        result += " " * (overall_precision - len(fract_part))
+        # add leading whitespaces
+        target_len = 15 + precision
+        result = " " * (target_len - len(result)) + result
     return result